chaadster

Hey Y'all,

While driving my Audi the other day, I was thinking about how nice it looks having the gentle red glow illuminating the area behind the door release handle, and what a nice addition it would be to my 928.

I checked my to usual sources for LEDs on the web and found these:

They flush mount, and so should be easy to position in the backing plate either at the top, or low behind the handle to avoid glare.

My question involves how to wire them to achieve (ideally), illumination that comes on with the ignition but switches off with a time delay after the ignition is killed.

Does this sound possible?

I figured I could easily wire them into the door courtesy lights, but of course those only light (on my '88) when the door is open. I'd really like for the handle LEDs to light continuously while the car is running and for a short period after its shut down, so I can find the handle on my way out. Not that that's a problem, btw...

I was chatting with Andrew Olson, batting around ideas, but neither of us are particularly savvy in this department. Could I add an in-line capacitor on an ignition switched circuit to get the desired delay effect?

Any insight, preferably in rather plain English ( ) is appreciated!

macreel

chaad... I suppose you want both door handles illuminated ?

A time-delay relay (oh no, not another gremlin) might be the ticket.
You can get adustable devices in fairly small packages.

Maybe even mount it in a blank slot in CE panel ? III or XXVI ? fuse 12? 44?


G'luck.

danglerb

Main use is to show unfamiliar passengers where the door handle is? Wire it to the seatbelt not fastened switch.

chaadster

Macreel--thanks for the relay idea. That seems like the most straightforward way to get the desired effect.

I was hoping, for simplicity's sake, to keep the necessary wiring in the door; perhaps feeding off the power mirror circuit (that's ignition switched, right?) and wiring in something like this:
adjustable time delay relay 12v



Probably overkill, but what I found with an initial search, and the adjustable time would allow me to match the timed off of the interior lights (after the door is closed).

danglerb--my car does not have seat belt monitoring.

macreel

chaad... yep, something like that. Be sure it's a "delay on release".
Also, check Infitec, Amperite, Agastat, Magnecor, Potter & Brumfield, etc.
Delays can be set by: switches, ****, external resistor, jumpers.

Electrical characteristics above look ok.

The mirror power is from fuse #12 and the "15" bus.

G'luck.

Alan

Chad - The power mirrors in mine work all the time??
You could probably use a big capacitor and resistor network (to limit LED current and to limit Capacitor charging rate) in this particular application as long as you only need a very low level of illumination for a few second (<10)

Alan

danglerb

Proximity detector like the faucets etc. use, when anything gets close the LED comes on.

Maybe something tied to the brake lights and a full stop?

Also if the light was very dim and red, on anytime the lights are on might be ok.

Making it so it was only visible from the passenger seat might also make it less distracting.

j.kenzie@sbcglobal.net

I bought two "glow in the dark" stickers about 1/2" diameter from one of the big three. One for each door. Works fine, no wiring. Maybe even factory on some models, not sure.

Alan

My GTS has a small (~1/2" diameter) luminous dot on each door handle - do earlier models not have this?

Alan

greg928GTS

I would just hook them to the headlight circuit. I don't think they draw much juice.

My S8 has ambient cabin lighting and it's great. I'd love to have some in the GTS.

Normy

Well, I just got in from driving my new airport car- a '97 Jetta GLX, and it has interior lights that dim slowly when you leave the thing. I suspect this is a function of a relay. It occurs to me that if you mount this relay in a late model or........not-so late model Porsche that you can basically twist this relay and now you have exclusively porsche odd unsubstantiatiated lights.

Alan

Normy - unfortunately it seems not. These things handle a considerable power to dim - so are typically much larger than a plug in bosch relay.

Alan

Andrew Schauer

I've seen the glow in the dark/reflective dots on the door handles on quite a few 928s. If they weren't stock, I'd guess they were a pretty popular dealer option. Probably have fallen off the majority of the handles over the years though.

Alan

Andrew - this is not a stick on dot - or at least its recessed below flush into the door handle... They are not particularly bright - but they do show up in pitch black...

Alan

Alan

Chaad - so here is an idea for how:

12v ignition (15 bus) from somewhere: 100 ohms series resistance to the +ve plate of a 4700uF capacitor (with the -ve plate direct to Gnd), then 680 ohms to the +ve side of the LED with the negative to gnd. This will give you a not very bright LED but it will quickly fade on with the ignition and after the ignition is turned off it will give you about 10 seconds of illumination (fading out slowly). Try it and you can adjust both the capacitor size (bigger for longer) and the resistor to the LED to lower (for brighter but shorter time).

4700 uF capacitors are not too big in size to go in the door. You may want to put it all into a box to keep it tidy...

Alan